Northern Harrier (Circus cyaneus) Science Article 2
Egg and liver samples of Montagu’s and Marsh Harriers from the 1990’s were examined for their burden of DDT and PCB. The DDT burden in both species was distinctly higher in the eggs than in juveniles and adults, whereby the values for the adults were clearly higher than those for the juveniles. The composition of the DDT isomers of both species varies between the life stages. In the egg samples nearly only p,p’-DDE was found, while in the livers of the adults and more especially of the juveniles higher parts of p,p’-DDT were detected. In both species the PCB burden of the eggs and of the adults was clearly higher than that of the juveniles. The composition of the PCB mixtures of both species differed distinctly between each of the life stages. While the PCB mixtures in eggs and in the livers of adults are nearly identical, in the livers of juveniles a distinct shift to lower chlorinated congeners reaching higher parts of the PCB mixtures becomes evident. The changes in the composition of DDT and PCB mixtures in the different life stages reflect a new uptake of these xenobiotics with the food animals.
Eckhard Denker, Annegret Buthe, Doris Glimm, Manfred Holker, Werner Prunte und Theodor Trendelkamp, J. Ornithol. 144, 411-417 (2003)